path: root/third_party/nix/src/libexpr/value-to-json.cc

#include "value-to-json.hh"

#include <cstdlib>
#include <iomanip>

#include "eval-inline.hh"
#include "json.hh"
#include "util.hh"

namespace nix {

void printValueAsJSON(EvalState& state, bool strict, Value& v,
                      JSONPlaceholder& out, PathSet& context) {
  checkInterrupt();

  if (strict) {
    state.forceValue(v);
  }

  switch (v.type) {
    case tInt:
      out.write(v.integer);
      break;

    case tBool:
      out.write(v.boolean);
      break;

    case tString:
      copyContext(v, context);
      out.write(v.string.s);
      break;

    case tPath:
      out.write(state.copyPathToStore(context, v.path));
      break;

    case tNull:
      out.write(nullptr);
      break;

    case tAttrs: {
      auto maybeString =
          state.tryAttrsToString(noPos, v, context, false, false);
      if (maybeString) {
        out.write(*maybeString);
        break;
      }
      auto i = v.attrs->find(state.sOutPath);
      if (i == v.attrs->end()) {
        auto obj(out.object());
        StringSet names;
        for (auto& j : *v.attrs) names.insert(j.name);
        for (auto& j : names) {
          Attr& a(*v.attrs->find(state.symbols.create(j)));
          auto placeholder(obj.placeholder(j));
          printValueAsJSON(state, strict, *a.value, placeholder, context);
        }
      } else
        printValueAsJSON(state, strict, *i->value, out, context);
      break;
    }

    case tList1:
    case tList2:
    case tListN: {
      auto list(out.list());
      for (unsigned int n = 0; n < v.listSize(); ++n) {
        auto placeholder(list.placeholder());
        printValueAsJSON(state, strict, *v.listElems()[n], placeholder,
                         context);
      }
      break;
    }

    case tExternal:
      v.external->printValueAsJSON(state, strict, out, context);
      break;

    case tFloat:
      out.write(v.fpoint);
      break;

    default:
      throw TypeError(format("cannot convert %1% to JSON") % showType(v));
  }
}

void printValueAsJSON(EvalState& state, bool strict, Value& v,
                      std::ostream& str, PathSet& context) {
  JSONPlaceholder out(str);
  printValueAsJSON(state, strict, v, out, context);
}

void ExternalValueBase::printValueAsJSON(EvalState& state, bool strict,
                                         JSONPlaceholder& out,
                                         PathSet& context) const {
  throw TypeError(format("cannot convert %1% to JSON") % showType());
}

}  // namespace nix